Buttercup Posted September 16, 2011 Share Posted September 16, 2011 For me this is definately not a lounge topic but is there anyone who can solve this equation for me. I am in my final part of getting my GCSE maths and really have trouble with algebra. X squared plus 3 x - 5 = 0 also 3x +2y=3 and 5x-y=-8 I really am trying to understand it but could not do it at school and still cant. Why oh why do I need to know this to work with 3-4 year olds. Any help greatly appreciated. Buttercup Quote Link to comment Share on other sites More sharing options...
Guest Posted September 16, 2011 Share Posted September 16, 2011 I can not help. but i sympathise exactly, i took me four atempts to finally pass my GCSE maths, and can i remember any of it?, can i heck!. hopefully someone will be along that can help you. Dawn For me this is definately not a lounge topic but is there anyone who can solve this equation for me. I am in my final part of getting my GCSE maths and really have trouble with algebra. X squared plus 3 x - 5 = 0 also 3x +2y=3 and 5x-y=-8 I really am trying to understand it but could not do it at school and still cant. Why oh why do I need to know this to work with 3-4 year olds. Any help greatly appreciated. Buttercup Quote Link to comment Share on other sites More sharing options...
Rea Posted September 16, 2011 Share Posted September 16, 2011 Sorry all I see is a spilt box of stuff out of the playgroup cupboard My 18 yr old says 'no idea, I might have been able to do it once, but not now'. Good luck though Quote Link to comment Share on other sites More sharing options...
mundia Posted September 16, 2011 Share Posted September 16, 2011 Hi Buttercup, can I just clarify the first one is written correctly? Quote Link to comment Share on other sites More sharing options...
Melba Posted September 16, 2011 Share Posted September 16, 2011 Are you sure that's not x squared + 4x -5 = 0? In which case its a quadratic (x+5)(x-1)=0 and you can work out the two possible values of x which give 0 Then take the second and third equations, you need to multiply one of them by something so that the y term in each is the same. You can then subtract one from the other to get rid of the y's. In this case multiply the third equation by -2, which gives you 3x+2y=3 -10x+2y=16 Subtract the second equation from the first to get an equation for x Hopefully it will agree with one of the values from the first equation. ( have to admit all of the above was actually written by Mr Melba, not me.) Quote Link to comment Share on other sites More sharing options...
sunnyday Posted September 16, 2011 Share Posted September 16, 2011 Can I just ask which language are you using in this thread - it's all greek to me! Quote Link to comment Share on other sites More sharing options...
Rea Posted September 16, 2011 Share Posted September 16, 2011 It must be something of national importance which is on a need to know basis only Sunnyday. Its not for the likes of us so I'm not going to worry about it, I'm just glad there are people out there that understand and can keep us all safe Quote Link to comment Share on other sites More sharing options...
Guest Posted September 16, 2011 Share Posted September 16, 2011 For me this is definately not a lounge topic but is there anyone who can solve this equation for me. I am in my final part of getting my GCSE maths and really have trouble with algebra. X squared plus 3 x - 5 = 0 also 3x +2y=3 and 5x-y=-8 I really am trying to understand it but could not do it at school and still cant. Why oh why do I need to know this to work with 3-4 year olds. Any help greatly appreciated. Buttercup Quote Link to comment Share on other sites More sharing options...
janebe Posted September 18, 2011 Share Posted September 18, 2011 3x +2y=3 and 5x-y=-8 3x + 2y = 3 5x - y = -8 Multiply second equation by -2 so that both equations have 2y in them... 3x + 2y = 3 -10x + 2y = 16 Change the equations around so that 2y part is by itself (remember to change signs if you move anything from one side of an equation to the other to keep 'the balance') 2y = 3 -3x 2y = 16 + 10x Now the second part of each equation must also be equal to each other (as they are both equal to 2y)... 3 - 3x = 16 + 10x Put the xs on one side of the equation and the numbers on the other side (try to keep the xs positive as it makes it easier!!)... 3 = 16 + 10x + 3x 3 = 16 +13x 3 - 16 = 13x -13 = 13x Then divide both sides by 13 to get the value of x... -1 = x Now we know the value of x, substitute this value back into one of the initial equations (the simplest one and I would choose the one that you've already arranged so that the y is by itself!)... 2y = 3 - 3x 2y = 3 - 3(-1) 2y = 3 +3 2y = 6 Therefore y = 3 Lastly, always put both values back into the initial equations to check your results... 3x + 2y = 3 3(-1) + 2(3) = 3 -3 + 6 = 3 (i.e. correct!) 5x - y = -8 5(-1) - (3) = -8 -5 -3 = -8 (i.e. correct!) Hope that helps Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.